| Objective: Through the study of different radiotherapy sensitivity to miRNA,the sensitivity of miRNA was screened,To investigate the levels of miR-19 a expressions in cancer tissues of patients with radiation-sensitive and radiation-resistant cervical squamous cell carcinoma,and evaluate the potential of miR-19 a as biomarkers of cervical cancer,and the mechanism of its sensitivity to radiotherapy was analyzed.Methods: Collected 91 cases of cervical squamous carcinoma hospitalized from June2014 to September 2015 in xinjiang medical university affiliated tumor hospital hospitalization,The 12 samples were used for chip screening,6 cases in resistance group and 6 cases in sensitive group,and the difference miRNA of cervical cancer tissue samples with different radiotherapy sensitivity was selected by the chip.Among them,the expression level of mir-19 a in patients with recurrence and metastasis was significantly increased.RT-PCR results are in good agreement with chip results.41 cases in sensitive group and 38 cases in resistant group.Real time-PCR was used to detect the expressions of miR-19 a of between the two groups,to analyze its correlation with cervical cancer radiotherapy sensitivity.The diagnostic value of miR-19 a for radiosensitivity in human cervical cancer was assessed by receiver operator characteristic(ROC)curve.all patients are divided into low expression group and high expression group according to miR-19 a average expression level.The cervical squamous cell carcinoma cell line SiHa and the radiotherapy sensitive cervical squamous cell carcinoma cell line Me180 were selected as the experimental cell lines.On the one hand,miR-19a-mimic and miR-19a-inhibitor were transfected to Siha and Me180 cells,and the clone formation test was used to test the radiation sensitivity of cervical cancer cells.On the other hand,vector miR-19 a stable transfected by lentivirus in vitro and in vivo experiments to test cell radiosensitivity,through proliferation,cycle and apoptosis of experimental test may regulate the sensitivity of radiotherapy to preliminarily explore the mechanism of miR-19 a,The possible target gene of miR-19 a was preliminarily screened by using bioinformationsoftware and network.Results: The results of chip screening showed that the expression of miRNA-19 a was up-regulated in both the recurrent group and the distant transfer group.It is preliminarily conjectured that miRNA-19 a may be closely related to radiation resistance,recurrence and metastasis of cervical cancer cells.at the follow-up of 24-36 months,There was no significant difference between the two groups in age,clinical stage,SCC level,histological grade,local lymph node metastasis and tumor size(P > 0.05),The expression level of MiR-19 a was 4.01 ± 1.16 in resistant group and 1.39 ± 0.35 in sensitive group.The expression levels of miR-19 a were significantly higher in patients with in resistant group than insensitive group(P=0.03).For miR-19 a the area under ROC curve was 0.963.Follow-up results show The 1-year survival rate was 93.6%,and the3-year survival rate was 79.7%.The survival of patients with cervical cancer was analyzed by kaplan-meier curve,and the survival time after radiotherapy of miR-19 a low expression group was significantly higher than that of the high expression group,and the difference was statistically significant(P=0.000).In vitro test showed that two strains of cells transfected with miR-19a-mimic after radiotherapy decreased sensitivity,radiation sensitivity increased after transfection of miR-19a-inhibitor,construct the nude mice model with vector transfected miR-19 a cells has been slow virus again,results showed that had been transfected with miR-19 a tumor and compared with the control group is not sensitive to radiotherapy,miR-19 a inhibited the sensitivity of cervical squamous cell carcinoma cell proliferation assay and radiotherapy.Experiments show that the influence of transfection of nude mouse model of miR-19 a is not on proliferation of cervical cancer cell,apoptosis experiments showed that miR-19 a can inhibit the apoptosis induced by radiation.In addition,microRNA-19 a inhibits radiation sensitivity of cervical cancer cells by inhibiting radiation induced apoptosis.Through the prediction and analysis of biological target genes,the preliminary results show that the target genes such as PTEN,IGF2 R,CUL5,Bcl-2 and BAX may be regulated by miR-19 a.Further Western Blot assay was used to detect the expression level of apoptosis related protein.It was found that inhibition of MiR-19 a resulted in up regulation of BAX and down regulation of apoptosis protein Bcl-2.Conclusions: MiR-19 a is highly expressed in patients with radiation-resistant cervical squamous cell carcinoma.MiR-19 a is expected to be used as an indicator to predict the sensitivity of cervical cancer to radiotherapy. |
PDF Full Text Request